diff --git a/build.sbt b/build.sbt
index e3593c3e1..5f0413c2e 100644
--- a/build.sbt
+++ b/build.sbt
@@ -19,7 +19,7 @@ val coursierVersion = "1.1.0-M8"
 
 lazy val `lm-coursier` = project
   .in(file("modules/lm-coursier"))
-  .enablePlugins(ContrabandPlugin, JsonCodecPlugin)
+  .enablePlugins(ContrabandPlugin)
   .settings(
     shared,
     libraryDependencies ++= Seq(
diff --git a/modules/lm-coursier/src/main/contraband-scala/coursier/lmcoursier/CoursierConfigurationFormats.scala b/modules/lm-coursier/src/main/contraband-scala/coursier/lmcoursier/CoursierConfigurationFormats.scala
deleted file mode 100644
index f394dfb87..000000000
--- a/modules/lm-coursier/src/main/contraband-scala/coursier/lmcoursier/CoursierConfigurationFormats.scala
+++ /dev/null
@@ -1,43 +0,0 @@
-/**
- * This code is generated using [[http://www.scala-sbt.org/contraband/ sbt-contraband]].
- */
-
-// DO NOT EDIT MANUALLY
-package coursier.lmcoursier
-import _root_.sjsonnew.{ Unbuilder, Builder, JsonFormat, deserializationError }
-trait CoursierConfigurationFormats { self: sbt.internal.librarymanagement.formats.LoggerFormat with sbt.librarymanagement.ResolverFormats with sjsonnew.BasicJsonProtocol =>
-implicit lazy val CoursierConfigurationFormat: JsonFormat[coursier.lmcoursier.CoursierConfiguration] = new JsonFormat[coursier.lmcoursier.CoursierConfiguration] {
-  override def read[J](jsOpt: Option[J], unbuilder: Unbuilder[J]): coursier.lmcoursier.CoursierConfiguration = {
-    jsOpt match {
-      case Some(js) =>
-      unbuilder.beginObject(js)
-      val log = unbuilder.readField[Option[xsbti.Logger]]("log")
-      val resolvers = unbuilder.readField[Vector[sbt.librarymanagement.Resolver]]("resolvers")
-      val otherResolvers = unbuilder.readField[Vector[sbt.librarymanagement.Resolver]]("otherResolvers")
-      val reorderResolvers = unbuilder.readField[Boolean]("reorderResolvers")
-      val parallelDownloads = unbuilder.readField[Int]("parallelDownloads")
-      val maxIterations = unbuilder.readField[Int]("maxIterations")
-      val sbtScalaOrganization = unbuilder.readField[Option[String]]("sbtScalaOrganization")
-      val sbtScalaVersion = unbuilder.readField[Option[String]]("sbtScalaVersion")
-      val sbtScalaJars = unbuilder.readField[Vector[java.io.File]]("sbtScalaJars")
-      unbuilder.endObject()
-      coursier.lmcoursier.CoursierConfiguration(log, resolvers, otherResolvers, reorderResolvers, parallelDownloads, maxIterations, sbtScalaOrganization, sbtScalaVersion, sbtScalaJars)
-      case None =>
-      deserializationError("Expected JsObject but found None")
-    }
-  }
-  override def write[J](obj: coursier.lmcoursier.CoursierConfiguration, builder: Builder[J]): Unit = {
-    builder.beginObject()
-    builder.addField("log", obj.log)
-    builder.addField("resolvers", obj.resolvers)
-    builder.addField("otherResolvers", obj.otherResolvers)
-    builder.addField("reorderResolvers", obj.reorderResolvers)
-    builder.addField("parallelDownloads", obj.parallelDownloads)
-    builder.addField("maxIterations", obj.maxIterations)
-    builder.addField("sbtScalaOrganization", obj.sbtScalaOrganization)
-    builder.addField("sbtScalaVersion", obj.sbtScalaVersion)
-    builder.addField("sbtScalaJars", obj.sbtScalaJars)
-    builder.endObject()
-  }
-}
-}
diff --git a/modules/lm-coursier/src/main/scala/coursier/lmcoursier/CoursierLibraryManagementCodec.scala b/modules/lm-coursier/src/main/scala/coursier/lmcoursier/CoursierLibraryManagementCodec.scala
deleted file mode 100644
index b5cfc104d..000000000
--- a/modules/lm-coursier/src/main/scala/coursier/lmcoursier/CoursierLibraryManagementCodec.scala
+++ /dev/null
@@ -1,13 +0,0 @@
-package coursier.lmcoursier
-
-import sbt.librarymanagement.LibraryManagementCodec
-
-trait CoursierLibraryManagementCodec
-    extends sjsonnew.BasicJsonProtocol
-    with LibraryManagementCodec
-    // with sbt.internal.librarymanagement.formats.GlobalLockFormat
-    with sbt.internal.librarymanagement.formats.LoggerFormat
-    with sbt.librarymanagement.ResolverFormats
-    with CoursierConfigurationFormats
-
-object CoursierLibraryManagementCodec extends CoursierLibraryManagementCodec
diff --git a/modules/lm-coursier/src/main/scala/coursier/lmcoursier/CoursierModuleDescriptor.scala b/modules/lm-coursier/src/main/scala/coursier/lmcoursier/CoursierModuleDescriptor.scala
index 4e8311045..f30bf9732 100644
--- a/modules/lm-coursier/src/main/scala/coursier/lmcoursier/CoursierModuleDescriptor.scala
+++ b/modules/lm-coursier/src/main/scala/coursier/lmcoursier/CoursierModuleDescriptor.scala
@@ -1,7 +1,6 @@
 package coursier.lmcoursier
 
 import sbt.librarymanagement._
-import sjsonnew.support.murmurhash.Hasher
 
 final case class CoursierModuleDescriptor(
   descriptor: ModuleDescriptorConfiguration,
@@ -17,8 +16,6 @@ final case class CoursierModuleDescriptor(
   def moduleSettings: CoursierModuleSettings =
     CoursierModuleSettings()
 
-  lazy val extraInputHash: Long = {
-    import CustomLibraryManagementCodec._
-    Hasher.hash(conf).toOption.fold(0L)(_.toLong)
-  }
+  lazy val extraInputHash: Long =
+    conf.##
 }
diff --git a/modules/lm-coursier/src/main/scala/coursier/lmcoursier/CustomLibraryManagementCodec.scala b/modules/lm-coursier/src/main/scala/coursier/lmcoursier/CustomLibraryManagementCodec.scala
deleted file mode 100644
index 0a608c129..000000000
--- a/modules/lm-coursier/src/main/scala/coursier/lmcoursier/CustomLibraryManagementCodec.scala
+++ /dev/null
@@ -1,37 +0,0 @@
-package coursier.lmcoursier
-
-import sbt.librarymanagement.Resolver
-import sjsonnew.JsonFormat
-
-object CustomLibraryManagementCodec extends CoursierLibraryManagementCodec {
-
-  private type ConfFormat = (
-    Vector[Resolver],
-    Vector[Resolver],
-    Boolean,
-    Int,
-    Int
-  )
-
-  private def from(c: CoursierConfiguration): ConfFormat =
-    (
-      c.resolvers,
-      c.otherResolvers,
-      c.reorderResolvers,
-      c.parallelDownloads,
-      c.maxIterations
-    )
-
-  private def to(c: ConfFormat): CoursierConfiguration =
-    CoursierConfiguration()
-      .withResolvers(c._1)
-      .withOtherResolvers(c._2)
-      .withReorderResolvers(c._3)
-      .withParallelDownloads(c._4)
-      .withMaxIterations(c._5)
-
-  // Redefine to use a subset of properties, that are serializable
-  override implicit lazy val CoursierConfigurationFormat: JsonFormat[CoursierConfiguration] =
-    projectFormat[CoursierConfiguration, ConfFormat](from, to)
-
-}